<template>
  <div class="container">
    <h2>子组件 {{ modelValue }}
      <button @click="fn">改变数据</button>
    </h2>
  </div>
</template>

<script>
export default {
  name: "Son1",
  props: {
    modelValue: {
      type: Number,
      default: 0
    }
  },
  setup(props, {emit}) {
    const fn = () => {
      // 改变数据
      emit('update:modelValue', 100)
    }
    return {fn}
  }
}
</script>

<style scoped>

</style>
